h2:not(:first-child) {
    padding-top: 10px;
    border-top: 1px solid #ccc;
}

ul {
    width: 200px;

    li {
        list-style: decimal-leading-zero;

        &:nth-child(odd) {
            background-color: #aaa;
        }
        &:nth-child(even) {
            background-color: lightblue;
        }
    }
}

.box {
    &:after {
        content: '';
        display: block;
        clear: both;
    }

    > div {
        width: 200px;
        height: 100px;
        float: left;
        margin: 10px;
        background-size: cover;
        box-shadow: 0 0 5px #ccc;
    }

    // url 需要使用 url-loader 处理
    .box1 {
        background-image: url("../images/1.png");
    }
    .box2 {
        background-image: url("../images/2.png");
    }
}

.click-button {
    width: 100px;
    height: 40px;
    margin: 10px;
}